Leas: Burlington Free Press got it right on F-35 sound level

Editor’s note: This op-ed is by James Marc Leas, a patent lawyer from South Burlington who has a background in physics and engineering. The Burlington City Council is scheduled to discuss the F-35 issue at its meeting June 18 at 7 p.m. at Contois Auditorium in City Hall.

In the article,”Vermont Guard commander defends basing of F-35s,” John Briggs at the Burlington Free Press got it right on sound level: The draft environmental impact statement (EIS) shows an increase in maximum takeoff sound during a “military power takeoff” from 94 to 115 decibels, and the report notes that each additional 10 decibels represents a doubling of sound. The report says that “data indicate that the F-35A would generate generally higher noise levels than the legacy aircraft (the F-16) it is replacing except in afterburner takeoff.”

The F-35 sound level of 115 decibels and the F-16 sound level of 94 decibels are the peak sound levels during takeoff when the planes are 1,000 feet above ground level assuming conditions like those at the Burlington Airport, according to the chart on page BR4-18 of the Air Force’s draft EIS.

As the Air Force draft EIS and the Free Press article point out, each additional 10 decibels represents a doubling of sound to the human ear. The 21 decibel difference is more than two doublings of the sound or more than four times louder.

Anyone who has heard it flying over knows the F-16 is very loud. Four times louder than the F-16 is very, very loud indeed.

The 65 decibel level that the article and the Air Force draft EIS say makes 1,366 houses “unsuitable for residential living” is an average sound level over 24 hours, according to the Air Force draft EIS.

The 115 decibel peak sound level of a squadron of F-35s flying over Winooski lasts only for minutes, yet it is so loud that it makes the average over 24 hours go above that 65 decibel threshold for about half the houses in Winooski as well as neighborhoods in Burlington, South Burlington, Williston and Colchester, according to a contour lines on a picture of the neighborhoods around the Burlington airport in the Air Force draft EIS.

The 115 decibel peak sound level of a squadron of F-35s flying over Winooski lasts only for minutes, yet it is so loud that it makes the average over 24 hours go above that 65 decibel threshold for about half the houses in Winooski as well as neighborhoods in Burlington, South Burlington, Williston and Colchester, according to a contour lines on a picture of the neighborhoods around the Burlington airport in the Air Force draft EIS.

By contrast, the 94 decibel peak sound level of the current F-16s flying over Winooski also lasts for minutes but according to a “baseline” contour line on that picture, the F-16 is not loud enough to make that average sound level over 24 hours go above that 65 decibel threshold for any of the houses in Winooski. The F-16 is loud enough, though, that the airport has purchased and slated for demolition over 120 houses in South Burlington because they fall in the zone above that 65 decibel 24-hour average sound level and turned that neighborhood into a wasteland.

Another chart, this one on page C8 of the Air Force draft EIS gives representative peak sound levels as various Air Force planes takeoff and reach different heights. Although the F-35 is omitted from this chart, the F-16 is included. The chart is not specific for the Burlington Airport, as is the chart on page BR4-18. Since the Air Force has declined to bring an F-35 to Burlington so we can hear one for ourselves, the chart provides another way to get a sense of the peak sound level of an F-35 using an F-16 — but flying lower. Plotting the data in this chart, the difference between the peak sound of an F-16 and an F-35 at the representative location is something like the difference between the peak sound of an F-16 on takeoff as it reaches 2,500 feet and an F-16 on takeoff as it reaches 400 feet above ground level. Since the 2,500 feet at the representative location has a sound level equal to that at 1,000 feet in Burlington, we can consider that the 400 feet at the representative location would also be substantially lower in Burlington. But even if we accept the 400 feet, it means the F-16 has to be very much closer to the ground to simulate the peak sound of the F-35.

Gen. Dubie’s remarks quoted in the Free Press article appear to be targeting those speaking out against the F-35. But, perhaps unknowingly, his remarks really disparage the Air Force itself because it is the Air Force draft Environmental Impact Statement that provides the information that shows that the F-35 is 21 decibels and more than four times louder than the F-16. While the F-35 may be acceptable for large military bases far from residential neighborhoods, 115 decibels is a grossly unacceptable increase in loudness over the very loud 94 decibel baseline for the F-16 at a commercial airport surrounded by residential communities. Particularly where affordable houses are at risk this is entirely unacceptable.

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  • My husband died many years ago and I have one precious video of him, just one problem with it, it is video taped out doors and the location in North Hollywood, California is one and a half (1 1/2) miles from the Burbank airport, which is a small jet airport.

    Ken is demonstrating how you care for a pet iguana, staring our pet “Ace”. He puts his harness and leash on him, as required by the wild game officer in N. Hllywd. and he puts him in a big round tub for a quick swim and clips his nails and gives him his Vet authorized pet vitamins and then a nice lunch of fresh fruit and vegetables and dog food, and strokes his back. Then the neighborhood kids pet him and take turns walking him on his leash.

    But for me, so many years later, I wish there wasn’t the constant sound of the small but very loud jets coming and going. It really ruins an otherwise cute video.

    So much for fun family videos out doors when the F-35s come.
    ~ ~ ~ ~ ~ ~
    Cris Ericson
    http://crisericson.com

  • Christian Noll

    I wish I could make the meeting this evening at Contois.

    It is sad that such vast economic stimulus is based on blowing people up, under the pretext of “Defense” or “Security.”

    The military is here to preserve the peace and I think thats what they should do.

    There is not one thing “Defensive” about the F-35. It is an attack aircraft with stealth and nuclear capabilities designed for “pre-emptive” attacks on foriegn nations.

    Why can’t our federal, state and local governments stimulate our economys on something other than “War” or killing?

    Thank you Mr Leas.

  • timothy price

    Northcom is the NWO military organization for the North American Union, the unconstitutional takedown of the USA. The F-35 is their huge money wanting war plane to impose military control, and also to convert what is left of Vermont’s civilian economy to a war based economy so that in the guns and butter debate, the jobs, jobs, jobs, idiot argument for these evil engines of waste will out vote peace loving patriots.

    The UN, NATO, Northcom, and the NWO will not destroy America, will not destroy Vermont, because we will not let them. Stand up to these toadies.

  • Jim Lynch

    You people are so sad. If the economy in that part of Burlington/Winooski does not benefit from the VNG then I hope your taxes continue to climb. Good luck with your little toad hunting Tim.

  • Typical rural nighttime ambient noise is 20-40 dBA and urban residential nighttime noise is 58-62 dBA. Higher noise levels adversely impact restful sleep of people; restful sleep is a basic requirement for good mental and physical health.

    Doubling the sound pressure level, SPL, increases the dB instrument reading by 6 dB.
    For example: If at 800 uPa (micropascal) the SPL = 20 log (800/20) = 32 dB, at 1600 uPa it is 38 dB, and at 3200 uPa it is 44 dB, where 20 micropascal is the lowest SPL the human ear can sense, it is used as the reference pressure.
    http://www.osha.gov/dts/osta/otm/noise/health_effects/soundpropagation.html

    The increase in SPL = 115 dBA (F-35) – 94 dBA (F-16) = 21 dBA. This appears to be an innocent number, but it is anything but.

    A 6 dBA increase means a doubling of SPL
    A 12 dBA increase means a quadrupling of SPL
    An 18 dBA increase means 8 times SPL
    A 21 dBA increase means between 8 and 16 times SPL

    A fly-over of an F-35 would have a 115 dBA – 60 dBA (nighttime residential) = 55 dBA greater sound; such a sound increase is sure to wake up everyone, except the dead.

    Remember : Each 6 dBA increase means a doubling of SPL
    24 dBA is 16x, 30 dBA is 32x, etc.

    Here are some common definitions often used in acoustics reports:

    LApeak is the maximum A-weighted SPL occurring within a specified time period.
    Lpeak is the maximum deviation of a signal from its mean value within a specified time period.
    LA1 is the A-weighted SPL that is exceeded 1 % of the time.
    LA10 is the A-weighted SPL that is exceeded 10% of the time.
    LA10(1 hr) is the A-weighted SPL that is exceeded 10% of the time within a 1 hour period.
    LA90 is the A-weighted SPL that is exceeded 90% of the time; usually the background SPL
    LAeq is the A-weighted SPL which over a period of time has the same sound energy as the time-varying noise.
    LA10 – LA90 is a measure of the “choppiness” of the noise.
    Ld = LAeq(15 hrs) is the A-weighted SPL of daytime noise 7AM – 10PM
    Ln = LAeq(9hrs) +10 dbA is the A-weighted SPL of max. allowed nighttime noise 10PM – 7AM
    C-weighted SPLs are required for LFN; A-weighing would render meaningless the SPLs of LFN.
    LCpeak is the maximum C-weighted SPL occurring within a specified time period.
    http://www.scribd.com/doc/43497999/Noise-Control-Acoustic-Units-Presentation

    The Massachusetts Department of Environmental Protection, MassDEP, measures noise levels at the complainant’s location and at other nearby locations that may be affected, such as residences and/or buildings with other sensitive receptors. If the noise level at a sensitive receptor’s location is more than 10 dBA above ambient, MassDEP requires the noise source to mitigate its impact.

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